Due to recent developments of protective armour, for instance the use of composite armour, the importance of a great armour piercing capability has increased. Thus longer and heavier hollow charges have been designed. In certain cases this can be accepted, for example for multipurpose shells or the like; but for such system equipments which are strictly optimized with respect to weight and available space, for double and tandem charges or the like, this method is unsuitable. In practice with today's technology the length and weight of the charges is approaching a limit.
This is one of the reasons for the recent development of missiles, projectiles or the like which are intended to pass the target and in which the warhead is initiated when the missile is above, at the side of or under the target; so that, the damaging effect is concentrated on the least protected sections of the target. In order to achieve a damaging effect the warhead then must be inclined with respect to the longitudinal axis of the missile.
If the target is a battle tank, the most damaging effect is achieved if the missile passes at a certain distance above the tank and the warhead is inclined so that it hits the tank from above, that is, hits the roof of the tank which as a rule is the most vulnerable part of the tank.
As a consequence of the velocity difference between the passing missile and the target, specific requirements are made on the hollow charge, however, in order to ensure a sufficient damaging effect. It has thus been shown that a conventional hollow charge having an acceptable static penetration capability often gives an unsatisfactory dynamic penetration. The reason for this is supposed to be the so-called "pole-vault effect" which happens when the rear parts of the hollow charge jet are "bent over" the newly made hole in the armour of the target due to the movement of the missile and due to the fact that the velocity of the rear parts of the hollow charge jet is less than the velocity of the front parts of the jet.
To compensate for a reduced penetration capability by increasing the length and weight is, as already mentioned, often impossible due to the limited space available. This is particularly the case for an over-flying missile in which the hollow charge is inclined with respect to the longitudinal axis of the missile, as this even more decreases the space available for incorporating the charge in the missile body and specifically limits the length of the charge.